Fork Spring / Tillotson Tarage – Gramma Precision

Fork spring Tillotson R33 is the most sensitive adjustment element of your carburettor HB-27 or HW-27. Its pressure force (expressed in grams) determines the threshold for the release of gasoline. A fine adjustment makes it possible to optimize the recovery at low speed and avoid congestion or impoverishment at the end of the straight line.

Choose your Tarage:

• 26 grs: Very tender. For maximum enrichment and ultra-fast opening.

• 31 grs: Tender. Ideal for cold or rain track conditions.

• 37 grs: Medium / Standard. The ideal compromise for most conditions.

• 42 grs: Hard. To stabilize the carburation and avoid spills on bumped tracks.

• 46 grs: Very hard. For strict control of very high-speed sealing.

Recommendations Manufacturers:

• Reference (29): Recommended rate for motor IAME X30.

• Reference (32): Recommended rate for motor IAME KA100.

The Magickart Commitment: Accuracy is done to the nearest gram. Magickart guarantees you the best stock and lowest price in Europe over the entire range of Tintson springs!

Michel's Council (Magickart): Which weight to choose?

"The choice of grammage is what separates a good driver from a champion. My expert advice: The lighter the spring (e.g. 26g), the earlier the tip opens, giving 'fat' to the acceleration. Conversely, a heavy spring (e.g. 46g) locks the tank better, ideal if your engine tends to clog in tight turns.

The Focus Pack:

• The Tarage Gauge: That's essential! Without it, you will never know if your 37g spring triggers well at the required pressure.

• The Air Box (NOX or Active): A change of spring changes the suction, make sure your air filter is clean so that you do not distort your tests.

• Membrane Kit (R32): A new spring works better with flexible membranes.

A little pro secret: Always note the gramming of your spring on your settings book. If the weather changes dramatically, going from a 37g to a 31g can give you the necessary 'jump' at the end of the curve. At Magickart, you are advised to have the complete set to never be caught off guard!"

How to change your R33 spring?

1. Secure Demountation: Unscrew the small screw (R17). Attention: Keep the lever with your thumb, as the spring can jump and lose instantly (especially light models!).

2. Cleaning of the seat: Check that no impurity is at the bottom of the spring well.

3. Positioning: Put the spring straight. The fork lever nipple must fit perfectly into the upper spring sparrow.

4. Height control: Once the screw is tightened, check with a rule that the lever is well aligned with the body of the carburettor.

5. Pressure test: Use your gauge. A spring of 37g will trigger earlier (lower pressure) than a spring of 46g.

Why is it so important? The balance between spring force and engine depression creates performance. If you change your category or engine (X30 vs KA100), the spring is the first part to adapt to make your carburation stable.